<?php

/**
 * Author : smallchicken
 * Time   : 2009年6月8日16:46:05
 * mode 1 : 强制裁剪，生成图片严格按照需要，不足放大，超过裁剪，图片始终铺满
 * mode 2 : 和1类似，但不足的时候 不放大 会产生补白，可以用png消除。
 * mode 3 : 只缩放，不裁剪，保留全部图片信息，会产生补白，
 * mode 4 : 只缩放，不裁剪，保留全部图片信息，生成图片大小为最终缩放后的图片有效信息的实际大小，不产生补白
 * 默认补白为白色，如果要使补白成透明像素，请使用SaveAlpha()方法代替SaveImage()方法
 *
 * 调用方法：
 *
 * $ic=new ImageCrop('old.jpg','afterCrop.jpg');
 * $ic->Crop(120,80,2);
 * $ic->SaveImage();
 * //$ic->SaveAlpha();将补白变成透明像素保存
 * $ic->destory();
 */
class ImageCrop {

    var $sImage;
    var $dImage;
    var $src_file;
    var $dst_file;
    var $src_width;
    var $src_height;
    var $src_ext;
    var $src_type;

    public function __construct($src_file, $dst_file = '') {
        $this->src_file = $src_file;
        $this->dst_file = $dst_file;
        $this->LoadImage();
    }

    public function SetSrcFile($src_file) {
        $this->src_file = $src_file;
    }

    public function SetDstFile($dst_file) {
        $this->dst_file = $dst_file;
    }

    /**
     * 加载源图
     */
    public function LoadImage() {
        list($this->src_width, $this->src_height, $this->src_type) = getimagesize($this->src_file);
        switch ($this->src_type) {
            case IMAGETYPE_JPEG :
                $this->sImage = imagecreatefromjpeg($this->src_file);
                $this->ext = 'jpg';
                break;
            case IMAGETYPE_PNG :
                $this->sImage = imagecreatefrompng($this->src_file);
                $this->ext = 'png';
                break;
            case IMAGETYPE_GIF :
                $this->sImage = imagecreatefromgif($this->src_file);
                $this->ext = 'gif';
                break;
            default:
                exit();
        }
    }

    /**
     * 保存图片
     * @param type $fileName
     */
    public function SaveImage($fileName = '') {
        $this->dst_file = $fileName ? $fileName : $this->dst_file;
        switch ($this->src_type) {
            case IMAGETYPE_JPEG :
                imagejpeg($this->dImage, $this->dst_file, 100);
                break;
            case IMAGETYPE_PNG :
                imagepng($this->dImage, $this->dst_file);
                break;
            case IMAGETYPE_GIF :
                imagegif($this->dImage, $this->dst_file);
                break;
            default:
                break;
        }
    }

    /**
     * 直接输出图像到浏览器
     */
    public function OutImage() {
        switch ($this->src_type) {
            case IMAGETYPE_JPEG :
                header('Content-type: image/jpeg');
                imagejpeg($this->dImage);
                break;
            case IMAGETYPE_PNG :
                header('Content-type: image/png');
                imagepng($this->dImage);
                break;
            case IMAGETYPE_GIF :
                header('Content-type: image/gif');
                imagegif($this->dImage);
                break;
            default:
                break;
        }
    }

    public function SaveAlpha($fileName = '') {
        $this->dst_file = $fileName ? $fileName . '.png' : $this->dst_file . '.png';
        imagesavealpha($this->dImage, true);
        imagepng($this->dImage, $this->dst_file);
    }

    /**
     * 直接输出图像到浏览器
     */
    public function OutAlpha() {
        imagesavealpha($this->dImage, true);
        header('Content-type: image/png');
        imagepng($this->dImage);
    }

    /**
     * 销毁图片
     */
    public function destory() {
        imagedestroy($this->sImage);
        imagedestroy($this->dImage);
    }

    /**
     * 裁剪
     * @param type $dst_width 图片宽度
     * @param type $dst_height 图片高度
     * @param type $mode 裁剪模式
     * @param type $dst_file 保存路径
     */
    public function Crop($dst_width, $dst_height, $mode = 1, $dst_file = '') {
        if ($dst_file)
            $this->dst_file = $dst_file;
        $this->dImage = imagecreatetruecolor($dst_width, $dst_height);

        $bg = imagecolorallocatealpha($this->dImage, 255, 255, 255, 127);
        imagefill($this->dImage, 0, 0, $bg);
        imagecolortransparent($this->dImage, $bg);

        $ratio_w = 1.0 * $dst_width / $this->src_width;
        $ratio_h = 1.0 * $dst_height / $this->src_height;
        $ratio = 1.0;
        switch ($mode) {
            case 1:        // always crop
                if (($ratio_w < 1 && $ratio_h < 1) || ($ratio_w > 1 && $ratio_h > 1)) {
                    $ratio = $ratio_w < $ratio_h ? $ratio_h : $ratio_w;
                    $tmp_w = (int) ($dst_width / $ratio);
                    $tmp_h = (int) ($dst_height / $ratio);
                    $tmp_img = imagecreatetruecolor($tmp_w, $tmp_h);
                    $src_x = (int) (($this->src_width - $tmp_w) / 2);
                    $src_y = (int) (($this->src_height - $tmp_h) / 2);
                    imagecopy($tmp_img, $this->sImage, 0, 0, $src_x, $src_y, $tmp_w, $tmp_h);
                    imagecopyresampled($this->dImage, $tmp_img, 0, 0, 0, 0, $dst_width, $dst_height, $tmp_w, $tmp_h);
                    imagedestroy($tmp_img);
                } else {
                    $ratio = $ratio_w < $ratio_h ? $ratio_h : $ratio_w;
                    $tmp_w = (int) ($this->src_width * $ratio);
                    $tmp_h = (int) ($this->src_height * $ratio);
                    $tmp_img = imagecreatetruecolor($tmp_w, $tmp_h);
                    imagecopyresampled($tmp_img, $this->sImage, 0, 0, 0, 0, $tmp_w, $tmp_h, $this->src_width, $this->src_height);
                    $src_x = (int) ($tmp_w - $dst_width) / 2;
                    $src_y = (int) ($tmp_h - $dst_height) / 2;
                    imagecopy($this->dImage, $tmp_img, 0, 0, $src_x, $src_y, $dst_width, $dst_height);
                    imagedestroy($tmp_img);
                }
                break;
            case 2:        // only small
                if ($ratio_w < 1 && $ratio_h < 1) {
                    $ratio = $ratio_w < $ratio_h ? $ratio_h : $ratio_w;
                    $tmp_w = (int) ($dst_width / $ratio);
                    $tmp_h = (int) ($dst_height / $ratio);
                    $tmp_img = imagecreatetruecolor($tmp_w, $tmp_h);
                    $src_x = (int) ($this->src_width - $tmp_w) / 2;
                    $src_y = (int) ($this->src_height - $tmp_h) / 2;
                    imagecopy($tmp_img, $this->sImage, 0, 0, $src_x, $src_y, $tmp_w, $tmp_h);
                    imagecopyresampled($this->dImage, $tmp_img, 0, 0, 0, 0, $dst_width, $dst_height, $tmp_w, $tmp_h);
                    imagedestroy($tmp_img);
                } elseif ($ratio_w > 1 && $ratio_h > 1) {
                    $dst_x = (int) abs($dst_width - $this->src_width) / 2;
                    $dst_y = (int) abs($dst_height - $this->src_height) / 2;
                    imagecopy($this->dImage, $this->sImage, $dst_x, $dst_y, 0, 0, $this->src_width, $this->src_height);
                } else {
                    $src_x = 0;
                    $dst_x = 0;
                    $src_y = 0;
                    $dst_y = 0;
                    if (($dst_width - $this->src_width) < 0) {
                        $src_x = (int) ($this->src_width - $dst_width) / 2;
                        $dst_x = 0;
                    } else {
                        $src_x = 0;
                        $dst_x = (int) ($dst_width - $this->src_width) / 2;
                    }

                    if (($dst_height - $this->src_height) < 0) {
                        $src_y = (int) ($this->src_height - $dst_height) / 2;
                        $dst_y = 0;
                    } else {
                        $src_y = 0;
                        $dst_y = (int) ($dst_height - $this->src_height) / 2;
                    }
                    imagecopy($this->dImage, $this->sImage, $dst_x, $dst_y, $src_x, $src_y, $this->src_width, $this->src_height);
                }
                break;
            case 3:        // keep all image size and create need size
                if ($ratio_w > 1 && $ratio_h > 1) {
                    $dst_x = (int) (abs($dst_width - $this->src_width) / 2);
                    $dst_y = (int) (abs($dst_height - $this->src_height) / 2);
                    imagecopy($this->dImage, $this->sImage, $dst_x, $dst_y, 0, 0, $this->src_width, $this->src_height);
                } else {
                    $ratio = $ratio_w > $ratio_h ? $ratio_h : $ratio_w;
                    $tmp_w = (int) ($this->src_width * $ratio);
                    $tmp_h = (int) ($this->src_height * $ratio);
                    $tmp_img = imagecreatetruecolor($tmp_w, $tmp_h);
                    imagecopyresampled($tmp_img, $this->sImage, 0, 0, 0, 0, $tmp_w, $tmp_h, $this->src_width, $this->src_height);
                    $dst_x = (int) (abs($tmp_w - $dst_width) / 2);
                    $dst_y = (int) (abs($tmp_h - $dst_height) / 2);
                    imagecopy($this->dImage, $tmp_img, $dst_x, $dst_y, 0, 0, $tmp_w, $tmp_h);
                    imagedestroy($tmp_img);
                }
                break;
            case 4:        // keep all image but create actually size
                if ($ratio_w > 1 && $ratio_h > 1) {
                    $this->dImage = imagecreatetruecolor($this->src_width, $this->src_height);
                    imagecopy($this->dImage, $this->sImage, 0, 0, 0, 0, $this->src_width, $this->src_height);
                } else {
                    $ratio = $ratio_w > $ratio_h ? $ratio_h : $ratio_w;
                    $tmp_w = (int) ($this->src_width * $ratio);
                    $tmp_h = (int) ($this->src_height * $ratio);
                    $this->dImage = imagecreatetruecolor($tmp_w, $tmp_h);
                    imagecopyresampled($this->dImage, $this->sImage, 0, 0, 0, 0, $tmp_w, $tmp_h, $this->src_width, $this->src_height);
                }
                break;
        }
    }

}
